Other Income And Expenses (Tables)

12 Months Ended

Dec. 31, 2011

Other Income And Expenses [Abstract]

Other Income And Expenses

	2011		2010		2009
Ameren:(a)
Miscellaneous income:
Interest and dividend income	$	4	$	5	$	2
Interest income on industrial development revenue bonds		28		28		28
Allowance for equity funds used during construction		34		52		36
Other		3		5		5
Total miscellaneous income	$	69	$	90	$	71
Miscellaneous expense:
Donations	$	8	$	19	$	12
Other		15		14		11
Total miscellaneous expense	$	23	$	33	$	23
Ameren Missouri:
Miscellaneous income:
Interest and dividend income	$	2	$	3	$	1
Interest income on industrial development revenue bonds		28		28		28
Allowance for equity funds used during construction		30		50		33
Other		1		2		1
Total miscellaneous income	$	61	$	83	$	63
Miscellaneous expense:
Donations	$	3	$	8	$	3
Other		7		5		4
Total miscellaneous expense	$	10	$	13	$	7
Ameren Illinois:
Miscellaneous income:
Interest and dividend income	$	1	$	1	$	6
Allowance for equity funds used during construction		4		2		2
Other		2		4		4
Total miscellaneous income	$	7	$	7	$	12
Miscellaneous expense:
Donations	$	1	$	5	$	4
Other		5		8		6
Total miscellaneous expense	$	6	$	13	$	10
Genco:
Miscellaneous income:
Other	$	1	$	1	$	1
Total miscellaneous income	$	1	$	1	$	1
Miscellaneous expense:
Other	$	—	$	1	$	1
Total miscellaneous expense	$	—	$	1	$	1

(a) Includes amounts for Ameren registrant and nonregistrant subsidiaries and intercompany eliminations.